The present invention relates generally to computer system management, and more particularly to feedback mechanism for controlling dispatching work tasks in a multi-tier storage environment.
As a storage system enforces its migration policies in order to better serve its users, time is required to prepare storage tiers. The time needed is a function of the amount of data that has to be moved between the storage tiers. Currently, a workload manager handling the dispatch of work using the storage tiers has no awareness of whether the storage system is undertaking to prepare the storage tiers to run the work. The workload manager will simply dispatch work when there are resources (CPU and Memory) to execute the work. The storage system may be in the process of migrating data to provide better workload throughput, and the process may not have been completed.
IBM Spectrum Scale™ provides tiered storage solutions. The solutions provide a policy language that can be used to govern the initial placement and migration of files placed on the storage. The policy language has access to information about the files it contains, and the rules can be constructed using that information. The policies are created by a storage administrator. The policies are able to use the file access time and calendar information to determine where data should be placed and where it should be moved to. The solutions are static. IBM Spectrum Scale™ does not have information about how the workload manager wants to use those storage tier resources. IBM Spectrum Scale™ is not able to overcommit the storage tiers because it has no knowledge about when and for how long the storage tiers will be used.
IBM Storwize® V7000 storage systems provide a simple to use means of defining storage tiers. It also automatically moves frequently accessed data to higher performance tiers. IBM Spectrum Control™ performs analytics on the storage tiers and can make recommendations on how to structure the data tiers. The administrator can use the recommendations to restructure the tiers. Spectrum Control™ provides a value to traditional storage solutions; however, Spectrum Control™ cannot handle the dynamic nature of the work which needs the storage, and it needs administrative intervention. EMC, HP and others use deduplication and compression to improve storage performance; however, they do not consider the workload scheduler.